Functional Limitations Of Attention Monitoring, Detailed Information - GF54.30-P-0020-01A

Model All (CAR) 

Overview 

This document contains information on:

• General 
• Function 
  • System feature impaired 
  • Individual handling characteristics 
  • Influence of time on system sensitivity 
  • Warning due to distraction or slight tiredness 
  • Change in driving behavior due to other factors 
  • Influence of semi-automatic steering on the steering pattern evaluation (vehicles with active driver assistance system  )

General 

Attention Assist can recognize typical signs of fatigue and lack of attention by the driver. This can lead to functional restrictions of the attention monitoring system due to various factors.

Function 

System features impaired 

Attention Assist can act unexpectedly under certain conditions:

• Driving time less than 30 min
• Poor road surface condition (e.g. surface undulations, pot holes)
• Strong crosswind
• Sporty driving style (e.g. high cornering speeds or strong accelerations)
• Partially automated steering or track guidance active (vehicles with active driver assistance system)
• Incorrectly set time
• Frequent lane and speed changes
• Operation of multimedia display
• Telephone calls

Individual handling characteristics 

The system detects changes in driving behavior. These changes cannot always be explained as fatigue or increasing inattentiveness, rather they can also be caused by peculiarities in steering behavior.

Certain driver types present specific challenges to the system, e.g. drivers with extremely smooth or extremely active steering behavior.

Influence of time on system sensitivity 

The system reacts in accordance with the human biorhythm depending on the time (e.g. the midday low). These results are determined representatively, but they may also differ on an individual basis.

Influence of driving time on system sensitivity 

The system reacts with increasing sensitivity as the driving time without a break increases. The weighting of the driving time is based on surveys and correspond to the average fatigue characteristics.

Warning due to distraction or slight tiredness 

The system not only warns in the case of fatigue, it can also warn when a change in driving behavior occurs (e.g. due to a significant distraction). Therefore, a warning is also correct because of increasing inattentiveness. The subjective fatigue sensitivity and the objective assessment variable determined by the system are different.

Change in driving behavior due to other factors 

As well as fatigue or increasing inattentiveness, other factors can also significantly alter steering behavior:

• Increasing slipperiness
• Worsening visibility
• Narrowing road
• Worsening road surface

The objective assessment variables identified by the system are thus considerably influenced.

Influence of semi-automatic steering on the steering pattern evaluation (vehicles with active driver assistance system) 

If the vehicle is steered semi-automatically, the system cannot clearly identify whether the driver is initiating the steering movements or not.